1. Field of the Invention
The present invention relates to a radiation detecting apparatus for detecting radiation, and in particular, a radiation apparatus used in medical apparatuses, non-destructive examination apparatuses, and the like, and to a method for manufacturing the same. The radiation herein includes α-rays, β-rays, and electromagnetic waves, such as X-rays and γ-rays.
2. Description of the Related Art
In the field of X-ray radiography, X-ray film systems have generally been applied which use a double-coated film and a fluorescent screen containing a phosphor layer. In addition, digital radiation detecting apparatuses have been used because they provide superior image characteristics and allow data to be captured into a networked computer system for sharing.
Among these digital radiation detecting apparatuses are high-sensitive, high-definition apparatuses, as disclosed in U.S. Pat. No. 6,262,422 and U.S. Pat. No. 6,469,305. Such radiation detecting apparatuses include: a photo-detector including two-dimensionally arranged photoelectric conversion devices, each conversion device including a photosensor and a thin-film transistor (TFT); and a phosphor layer for converting incident radiation into light capable of being sensed by the photoelectric conversion device. The two-dimensional photo-detector is covered with a protective layer for protecting the stiffness of the photoelectric conversion devices. In addition, moisture-resistant protective layers are provided between the phosphor layer and a reflection layer, and over the phosphor layer so as to cover the entire phosphor layer. A resin coat is further applied to the ends of the moisture-resistant protective layers. The moisture-resistant protective layers and resin coat prevent external water from permeating from the ends of the radiation detecting apparatus and enhance its durability.
The layers of the scintillator panel of a radiation detecting apparatus, such as a reflection layer, a protective layer, and an insulting layer, are formed of materials having largely different thermal expansion coefficients from each other. For example, amorphous carbon and glass have a thermal expansion coefficient in the range of 1 to 10×10−6/° C.; metals such as Al, in the range of 15 to 25×10−6/° C.; and common resins, in the range of 1 to 5×10−5/° C. Accordingly, the difference in displacement by a heat and humidity test among the layers is large. In order to enhance the durability of a radiation detecting apparatus, it is therefore important to increase adhesion between the layers so as to withstand displacement of each layer due to external influences, as well as to enhance moisture resistance. The above-described radiation detecting apparatuses have the following problems:
First, the phosphor layer may be broken or peeled from an underlayer, a protective layer of the phosphor layer overlying the photoelectric conversion devices, by a heat and humidity test because the adhesion between the phosphor layer and the underlayer is low.
Second, in connection with a corona discharge treatment, which is a common surface treatment for enhancing the adhesion of the underlayer to the phosphor layer, when the corona discharge treatment is applied to the underlayer overlying the photoelectric conversion devices of the sensor panel, current of the photoelectric conversion devices is likely to vary when the TFTs are in an off state, or when a wire of the photoelectric conversion devices is broken. Thus, it has been impossible to reform the surface of the underlayer without damaging the sensor panel.
An alternative to corona discharge treatment is vacuum plasma treatment, which produces the same results as corona discharge treatment. However, vacuum plasma treatment takes a long time and its process is complicated because it is performed under a high vacuum, and is thus undesirable.